Hexahydro-1H-furo(3,4-c)pyrrole compounds

ABSTRACT

Disclosed are compounds, having the following general formula, which are useful as analgesics and/or anti-inflammatory agents in living animals   WHEREIN R is a radical selected from the group consisting of hydrogen, aryl, alkenyl, aralkyl, halogen-substituted aralkyl, hydroxyl-substituted alkyl, arylsulfonyl, alicyclic, aroyl, alkylene dicarbonyl hexahydro-1H-furo(3,4-c)pyrrole, alkanoyl, arylene dicarbonyl hexahydro-1H-furo(3,4-c)pyrrole, halogensubstituted aroyl, arylethanoyl, halogen-substituted arylalkanoyl, halogen-substituted phenoxyalkanoyl, heteroaroyl, haloalkyl-substituted aroyl, alkyl-substituted aroyl, monoalkoxysubstituted aroyl, arylalkenoyl, hexahydrobenzoyl, alkanoyloxysubstituted aroyl, hydroxyl-substituted aroyl, and the pharmacologically acceptable acid addition salts thereof.

United States Patent Miller Oct. 7, 1975 HEXAHYDRO- l l-l-FURO(3,4-C )PYRROLE COMPOUNDS OTHER PUBLlCATIONS Chemical Abstracts, Vol. 77, Par. 151,3683.

Primary ExaminerElbert L. Roberts CH OCOCH CH -0 CH i 2 3 (CH3O)2C(CH3)2 cn -o cm l cn -0 cu o 2 o cn -o CH3 (lVl (Niel 0 i N- CH2C6H5 (Xlg cu ou CH OH 5 7 ABSTRACT Disclosed are compounds, having the following general formula, which are useful as analgesics and/or anti-infiammatory agents in living animals wherein R is a radical selected from the group consisting of hydrogen, aryl, alkenyl, aralkyl, halogensubstituted aralkyl, hydroxyl-substituted alkyl, arylsulfonyl, alicyclic, aroyl, alkylene dicarbonyl hexahydrolH-furo(3,4-c)pyrrole, alkanoyl, arylene dicarbonyl hexahydrol H-furo( 3 ,4-c )pyrrole, halo gen-substituted aroyl, arylethanoyl, halogen-substituted arylalkanoyl, halogen-substituted phenoxyalkanoyl, heteroaroyl, haloalkyl-substituted aroyl, alkyl-substituted aroyl, monoalkoxy-substituted aroyl, arylalkenoyl, hexahydrobenzoyl, alkanoyloXy-substituted aroyl, hydroxylsubstituted aroyl, and the pharmacologically acceptable acid addition salts thereof.

19 Claims, 1 Drawing Figure CH OCOCH Trans (XIX) e n cu un Trans H US. Patent (VII) Oct. 7,1975

:- CH 0COCH HEXAHYDRO- l H-FURO( 3 ,4-C )PYRROLE COMPOUNDS wherein R is a radical selected from the group consisting of hydrogen, aryl, alkenyl, aralkyl, halogensubstituted aralkyl, hydroxyl-substituted alkyl, arylsulfonyl, alicyclic, aroyl, alkylene dicarbonyl hexahydrolH-furo(3,4-c)pyrrole, alkanoyl, arylene dicarbonyl hexahydrol H-furo( 3,4-c )pyrrole, halogen-substituted aroyl, arylethanoyl, halogen-substituted arylalkanoyl, halogen-substituted phenoxyalkanoyl, heteroaroyl, haloalkyl-substituted aroyl, alkyl-substituted aroyl, monoalkoxy-substituted aroyl, arylalkenoyl, hexahydrobenzoyl, alkanoyloxy-substituted aroyl, hydroxylsubstituted aroyl, and the pharmacologically acceptable acid addition salts thereof.

For purposes of exemplification and not limitation, the above radicals designated R in relation to formula (a) include the following within their scope. The term aryl as used herein by itself or in combination with other radicals is used to denote radicals, such as phenyl and naphthyl. By alkenyl is intended, for example, straight and branched chain radicals containing from 2 to carbon atoms. The term aralkyl includes, for example, benzyl, phenethyl, methylbenzyl, 3- naphthylethyl, and 3-phenpropyl, wherein the alkyl portion of said radical contains from 1 to 10 carbon atoms. When halogen is referred to in relation to any of the radicals represented by R, all halogens are intended, and thus, fluorine, chlorine, iodine, and bromine are included; however, fluorine, chlorine and bromine are preferred. The term hydroxyl-substituted alkyl used herein is to denote alkyl radicals having from 1 to 10 carbon atoms substituted with at least 1, and no more than 6, hydroxyl groups. The radical arylsulfonyl" includes, for example, benzenesulfonyl and naphthalenesulfonyl. For example, alicyclic includes cycloalkyl radicals having from 3 to 8 ring carbon atoms, such as, cyclopropyl, cyclopentyl, cyclohexyl, and cycloheptyl. Aroyl, as used herein by itself or in combination with other radicals, includes unsubstituted radicals, for example, naphthoyl and benzoyl. Alkanoyl as used herein in combination with other radicals includes such radicals having from 2 to 10 carbon atoms, for example, isobutyroyl, propionyl, acetyl, and caproyl. Therefore, the term arylalkanoyl includes radicals such as, for example, phenylacetyl, phenylcaproyl and naphthylpropionyl. When used by itself the term alkanoyl is used herein to define such radicals containing from 2 to 18 carbon atoms. The radical heteroaroyl" includes, for example, nicotinoyl and thenoyl. When the term alkyl is used herein in combination with another radical to represent R above, it denotes straight and branch chain alkyl radicals containing from I to 10 carbon atoms. For example, the alkyl portion of an alkyl-substituted aroyl radical will contain from 1 to 10 carbon atoms and the aroyl radical will be substituted with at least 1 and no more than 5 such alkyl groups, preferably 1 to 3 such alkyl groups. Haloalkyl-substituted aroyl radicals include aroyl substituted with at least 1 and no more than 3 haloalkyl radicals each of which contains from 1 to 10 carbon atoms and at least 1 and no more than 6 halogen atoms. The alkoxy portion of the monoalkoxy substituted benzoyl radical contains from 1 to 10 carbon atoms and includes, for example, methoxybenzoyl and pentoxybenzoyl. The term arylalkenoyl" as used herein includes radicals, such as cinnamoyl and other such radicals, wherein the alkenoyl portion of the radical contains from 2 to 10 carbon atoms. The term alkanoyloxy-substituted aroyl, as used herein, includes radicals, such as acetoxybenzoyl and acetoxynaphthoyl, wherein the alkanoyloxy portion of the radicals contains from 2 to 10 carbon atoms and the aroyl radical is substituted with at least 1 and no more than 3 alkanoyloxy radicals. Hydroxyl-substituted aroyl is used herein to denote aroyl radicals which are substituted with at least I and no more than 3 hydroxyl groups. The terms halogen-substituted aralkyl," halogensubstituted aroyl, halogen-substituted arylalkanoyl, and halogen-substituted phenoxyalkanoyl" are used to indicate such radicals which are substituted with at least 1 and no more than 5 halogen atoms, preferably 1 to 3 halogen atoms.

in a preferred subclass of the present invention, R in formula (a) above is selected from the group consisting of: hydrogen; alkylene (C to C dicarbonyl hexahydro-lH-furo(3,4-c) pyrrole; phenylene dicarbonyl hexahydrolH-furo(3,4-c) pyrrole; phenyl; phenylacetyl; monoalkoxy (C, to C substituted benzoyl; phenylalkyl where the alkyl constituent thereof contains from 1 to 4 carbon atoms such as phenylpropyl, benzyl, and phenethyl; alkenyl (C and C mono-, di-, or tri-halogen substituted phenylalkyl where the alkyl group contains from 1 to 4 carbon atoms and the halogen is substituted on the phenyl ring; benzoyl; mono-, di-, or tri-halogen substituted benzoyl; mono-, di-, or tri-alkyl (C to C substituted benzoyl; mono-, di-, or tri-halogen substituted phenylalkanoyl wherein the alkanoyl group contains from 2 to 4 carbon atoms and the halogen is on the phenyl ring; hexahydrobenzoyl; phenylalkenoyl wherein the alkenoyl group is a lower alkenoyl containing from 3 to 5 carbon atomss; phenylethanoyl; halogen substituted phenoxyalkanoyl wherein the alkanoyl group contains from 1 to 4 carbon atoms and the phenoxy ring is substituted with from 1 to 3 halogen atoms; alkanoyl (C to C haloalkyl (C to C mono-, di-, or tri-substituted benzoyl wherein the haloalkyl group contains from l to 5 halogen atoms; monoor di-hydroxyl substituted alkyl where the alkyl group contains from I to 4 carbon atoms; phenylsulfonyl; monoor di-hydroxyl substituted benzoyl; nicotinoyl; monoor di-alkanoyloxy (C, to C substituted benzoyl; thenoyl; and cycloalkyl (C to C When halogen is referred to in this subclass, all halogens are intended; however, fluorine,chlorine, and bromine are preferred. In this preferred subclass, the above radicals, representing R in formula (a) above, can be substituted suitably in any of the ortho, meta, or para positions on the ring or any combination thereof unless otherwise directly indicated. For example, ring structures of the present preferred species of substituent R in formula (a) may be substituted in two ortho positions or two meta positions and/or the para position, or one ortho and one para position or any desired position combinations thereof.

The terms lower alkyl, lower alkoxy, lower haioalkyl, lower alkanoyl, and lower alkanoyloxy can be used to describe such radicals as referred to above in the preceding paragraph when they contain up to four carbon atoms.

Pharmacological studies indicate that the hexahydrolH-furo(3,4-c)pyrrole compounds of the present invention are effective in alleviating pain in living animal bodies, more especially mammalian bodies. In general, the present compounds exhibit analgesic and/or antiinflammatory activity. Test results in laboratory animals indicate that all of the subject compounds have analgesic activity except where R in formula (a) above is benzyl, hexahydrobenzoyl, o-acetoxybenzoyl, or phenylene dicarbonyl hexahydro-lH-furo(3,4-c)pyrrole and these compounds exhibit anti-inflammatory activity. As indicated, many of the present compounds exhibit analgesic/antiinflammatory activity; and in addition, some of the present compounds also exhibit antipyretic activity.

In a further preferred subclass of the present invention, R in formula (a) above is selected from the group consisting of phenethyl, chlorophenethyl, hydrogen, cyclohexyl, benzoyl, benzyl, chlorobenzoyl, phenylacetyl, chlorophenylacetyl, chlorophcnoxyacetyl, propionyl, nicotinoyl, trifluoromethylbenzoyl, dimethylbcnzoyl, thenoyl, trimethylbenzoyl, propenyl, hydroxyethyl, benzenesulfonyl, hydroxybenzoyl, cinnamoyl, naphthoyl, and the pharmacologically acceptable acid addition salts thereof.

In another preferred subclass of the present invention, R in formula (a) above is selected from the group consisting of hydrogen, o-acetoxybenzoyl, 2,4,6- trimethylbenzoyl, 2,6-dimethylbenzoyl, ohydroxybenzoyl, p-chlorophenethyl, benzyl, cyclohexyl, phenyl, benzoyl, l-naphthoyl, p-chlorobenzoyl, m-chlorobenzoyl, o-chlorobenzoyl, m-trifluoromethylbenzoyl, cinnamoyl, o-chlorophenylacetyl, mchlorophenylacetyl, p-chlorophenylacetyl, hexahydrobenzoyl, propenyl, m-methoxybenzoyl, thenoyl, phenethyl, phenylacetyl, p-chlorophenoxyacetyl, propionyl, nicotinoyl, hydroxyethyl, benzenesulfonyl, and the pharmacologically acceptable acid addition salts thereof.

Among the novel compounds of the present invention are, for example: hexahydro-lH-furo(3,4- c)pyrrole hydrochloride; 5phenylacetyl-hexahydrolH-furo( 3,4-c )pyrrole; S-benzoyl-hexahydrol H- furo( 3,4-c )pyrrole; 5-( lnaphthoyl )-hexahydrol H- furo (3,4-c)pyrrole; 5-(p-chlorobenzoyl)-hexahydrolH-furo( 3 ,4-c) pyrrole; 5-( m-chlorobenzoyl hexahydro-1-H-furo(3,4-c)pyrrole; 5 chlorobenzoyl)-hexahydro-1 H-fur0(3 ,4-c)pyrrole; (m-trifluoromethylbenzoyl)-hexahydr0-l H-furo(3 ,4-

c )pyrrole; 5-(o-chlorophenylacetyl)-hexahydro-1H- furo( 3,4-c )pyrrole; 5-( m-chlorophenylacetyl hexahydrol H-furo( 3,4-c )pyrrole; S-(pchlorophenylacetyl)-hexahydro-1H-furo(3,4-

c )pyrrole; 5-hexahydrobenzoylhexahydro-1H- furo( 3,4-c )pyrrole; 5-propionyl-hexahydrol H- furo( 3,4c )pyrrole; 5-( m-methoxybenzoyl )-hexahydrolH-furo( 3 ,4c )pyrrole; 5-(2thenoyl)-hexahydro-1H- furo( 3,4-pyrrole; 5-nicotinoyl-hexahydrolH-furo( 3 ,4-

c)pyrrole hydrochloride; 5-(p-chlorophenoxyacetyl)- hexahydrol H-furo(3,4-c)pyrrolc hydrochloride; 5-(oacetoxybenzoyl )-hexahydrol H-furo( 3,4-c )pyrrole;

5-( 2,4,6-trimethylbenzoyl )-hexahydrol Hfuro( 3,4-

0 )pyrrole; 5-( 2,6-dimethylben2oyl )-hexahydrol H- furo( 3,4-c )pyrrole; 5( o-hydroxybenzoyl hexahydrol H-furo( 3,4-c )pyrrole; 5,5 -adipyl-bis[hex ahydrol H-furo( 3,4-c )pyrrole]; 5,5 '-terephthaloyl-bis- [hexahydrol H-furo-( 3,4-c )pyrrole 5-allylhexahydrol H-furo( 3 ,4-c )pyrrole acetate; 5-( 2- hydroxyethyl )-hexahydrol H-furo( 3 ,4-c )pyrrole sulfate; S-phenethyl-hexahydrol H-furo( 3 ,4-c )pyrrole hydrochloride; 5-(p-chlorophenethyl)hexahydro-1H- furo( 3,4-c )pyrrole hydrochloride; 5-benzyl-hexahydrolH-furo(3,4-c)pyrrole hydrochloride; 5-cyclohexylhexahydrol H-furo( 3,4-c )pyrrole hydrochloride; 5- phenyl-hexadhydrol H-furo( 3 ,4-c )pyrrole hydrochloride; 5-( benzenesulfonyl )-hexahydrol H-furo( 3,4- c)pyrrole; and the pharmacologically acceptable acid addition salts of such basic compounds.

The immediate precusor for making most of the novel compounds of the present invention is hexahydro-lH-furo(3,4-c) pyrrole. This compound, as shown in the accompanying schematic drawing, can be prepared by several different routes or processes. It will be noted in the following description and examples that the Roman numerals used to identify the various compounds are identical to and correspond to those used in the accompanying schematic drawing to identify like products.

Using 3,4-bis( acetoxymethyl)furan (l) as the starting material, 3,4-bis( hydroxymethyl)furan (ll) can be suitably prepared via either a methanolysis or hydrolysis reaction process as illustrated in following Examples 1 and 2. The compound 3,4-bis(acetoxymethyl)furan (I) can be purchased, for example, from the Aldrich Chemical Co., lnc., Milwaukee, Wis, or prepared by methods described by H. Williams, P. Kaufmann and H. S. Mosher, Journal Organic Chemistry 20, ll39l (l955), K. Alder and H. F. Rickett, Berichte der Deutschen Chemischen Gesellschaft 70, 1354 1935), and E. C. Kornfcld and R. G. Jones, Journal Organic Chemistry 19, l67l-l680 (1954).

Using one of the optional routes of the present invention, 3,4-bis( hydroxymethyl )furan (ll) can be hydrogenated to form a cis-trans mixture of 3,4- bis(hydroxymethyl)tetrahydrofuran (lll) as shown in Example 3. This isomeric mixture (lll) in turn can be separated by forming the isopropylidene ketal (IV) of the cis-isomer with 2,2-dimethoxypropane as illustrated in Example 4. If desired, suitable ketals other than the isopropylidene ketal can be prepared from the cis-isomer in order to obtain the desired separation. The trans-isomer does not form a ketal. Ketal (lV) can then by hydrolyzed in an acidic aqueous solution as shown in Example 5 to form cis 3,4-bis(hydroxymethyl) tetrahydrofuran (Vl).

Alternatively, 3,4-bis(hydroxymethyl)furan (ll) can be reacted with 2,2-dimethoxypropane in an acidic aqueous solution as shown in Example 6 to prepare the isopropylidene ketal (Vll) of Compound (ll). The ketal (VII) in turn can be hydrogenated as shown in Example 7 to form ketal (lV), which in turn can be hydrolyzed in an acidic-aqueous solution to cis 3,4 bis( hydroxymethyl )tetrahydrofuran (Vl Continuing in the synthesis of the subject compounds, one mole cis-3,4-bis(hydroxymethyl)tetrahydrofuran (VI) is reacted with 2 moles of ptoluenesulfonyl chloride in pyridine to prepare cis 3,4- bis(tosyloxymethyl)tetrahydrofuran (VII). This compound, (VIII), can in turn be reacted with an ammoniaalcohol solution under pressure as illustrated in Example 12 to form hexahydro-lH-furo(3,4-c)pyrrole (X). Alternatively, cis 3,4-bis(tosyloxymethyl)tetrahydrofuran (VII) can be reacted with benzylamine as shwon in Example to form S-benzyl-hexahydro-lH-furo(3,4- c)pyrrole (IX). This product, (IX), in turn can be debenzylated as shown in Example I l to form hexahydro-l(3,4-c)pyrrole (X). All of the novel compounds of the present invention as well as those utilized in the claimed method of treatment are cis-isomers.

Using another route as shown in the accompanying schematic, one mole of the mixture of the cis-trans 3,4-

bis (hydroxymethyl)tetrahydrofuran (III) can be reacted with p-toluenesulfonyl chloride according to the process of Example 9 to form a cis-trans mixture of 3,4- bis(tosyloxymethyl)tetrahydrofuran (XIX). this product, (XIX), can in turn be reacted with benzylamine according to the process of Example 10 to form 5-benzyl hexadro-lH-furo(3,4-c)pyrrole (IX) from the cis 3,4- bis(tosyloxymethyl)tetrahydrofuran. S-Benzyl hexahydro-lH-furo (3,4-c)pyrrole (IX) is separated from the reaction product mixture by distillation at about 95 to 105C. at 0.15 mm Hg. This product in turn can be debenzylated according to the method of Example 11 to form hexahydro- 1 -H-furo(3,4-c )pyrrole.

Alternatively, the cis-trans mixture of 3,4- bis(tosyloxymethyl)tetrahydrofuran (XIX) can be reacted with an ammonia-alcohol solution under pressure using the process of Example 12 to form hexahydrolH-furo(3,4-c )pyrrole (X) which can be separated from the reaction product mixture by distilling out at about 182C. to 188C.

While the above processes describe the reaction of 3,4-bis(tosyloxymethyl)tetrahydrofuran with amines, such as ammonia and benzylamine, to give hexahydro- 1H-furo( 3,4-c) pyrroles, it should be recognized by one skilled in the present art that the tosyloxy group can be replaced by other sulfonate-bearing groups (e.g., methanesulfonyloxy) and halogens (e.g., chlorine).

The various reactions and processes discussed above and disclosed in the accompanying drawing are more particularly described in following Examples 1 to 12.

EXAMPLE I Methanolysis of 3,4-Bis( Acetoxymethyl)Furan Methanol (2200 ml) was placed in a 5 liter, threeneck flask and 3 grams of sodium were added in small portions. The flask was equipped with a mechanical stirrer, an 8 inch Vigreaux column connected with a distillation head and condenser. After the sodium was completely dissolved, 1374 grams (6.48 moles) of EXAMPLE 2 Hydrolysis of 3,4-Bis( Acetoxymethyl)Furan CH OCOCH Aqueous 3,4-Bis(acetoxymethyl)furan, represented by formula (I), 1 kg, 4.71 moles) was placed in a three-neck flask equipped with a mechanical stirrer, thermometer, condenser, and dropping funnel. A solution of 500 grams (12.5 moles) of sodium hydroxide in 1500 ml water was added slowly through the dropping funnel. After one hour the reaction became exothermic and the temperature rose to 74C. Hydrolysis was followed by gas liquid chromatographic analysis (Column 2' Carbowax M, temperature 190C). The reaction mixture was then cooled (ice water bath) to room temperature and the product was extracted with diethyl ether. After five extractions (1 pound diethyl ether each time), the reaction mixture was concentrated (until salts began to precipitate) and extracted in a continuous extractor. The gas liquid chromatography analysis indicated that the hydrolysis was quantitative.

EXAMPLE 3 Hydrogenation of 3,4-bis(I-Iydroxymethyl) Furan Preparation of cis and trans O 3 ,4- B1s( Hydroxymethyl )Tetrahydrofuran HOCH CH OH HOCH- H OH (Mixture Q of cis and trans (III) isomers) 3,4-Bis(hydroxymethyl)furan, represented by formula (II), was hydrogenated to a mixture of cis and trans 3,4-bis (hydroxymethyl)tetrahydrofuran (III) (approximately 1:1) under the following conditions:

Temperature: 120C. 1

Time: 3 hours Pressure (H 1150-1200 Psig A typical charge: Diol II 800 grams Standard Ni(23%) grams Ethanol 1300 ml The completion of the reaction was determined by gas liquid chromatographic analysis (2' Carbowax 20M column at 235C.). After completion of the reaction, the catalyst was filtered and the ethanol removed under reduced pressure.

EXAMPLE 4 Separation of cis-trans 3,4-Bis (Hydroxymethyl)Tetrahydrofuran Formation of lsopropylidene Ketal of cis-3 ,4-Bis( Hydroxymethyl )Tetrahydrofuran The separation of cis-trans isomers was accomplished by forming the isopropylidene ketal (IV) of the cisisomer iwth 2,2-dimethoxypropane. The trans-isomer does not fomi a ketal. Ketal (IV) was separated from the trans-isomer by distillation.

I082 Grams (8.16 moles) of the diol, represented by formula (III), and 2,2-dimethoxypropane 1270 grams, 50% excess) were placed in a three-neck flask equipped with a thermometer, mechanical stirrer, and consenser and then l.0 gram of p-toluenesulfonic acid monohydrate was added. As soon as the acid was added, the solution became clear and the temperature dropped to 16C. The reaction mixture was stirred for 0.5 hour and then methanolic sodium hydroxide was added to the reaction mixture to make the reaction mixture slightly alkaline, that is, a pH of about 8 to 9.

Completion of the reaction was determined by gas liquid chromatography.

After neutralization, the excess dimethoxypropane was stripped under reduced pressure and the ketal represented by formulaa (IV) distilled at 55 to 62C./().45 to 0.50 mm Hg. The trans 3,4-bis(hydroxymethyl)furan remained as pot residue or can be distilled.

EXAMPLE Hydrolysis of Ketal (IV) Isolation of cis 3 ,4-Bis( Hydroxymethyl )Tetrahydrofuran (VI) cis 800 Grams (4.65 moles) of the ketal, represented by formula (IV), were hydrolyzed with 1.5 grams of p-toluenesulfonic acid monohydrate and 200 ml of H 0. The reaction mixture was stirred for 0.5 to 1 hour at room temperature. The progress of the hydrolysis was followed by gas liquid chromatography. The reaction mixture was then neutralized with aqueous sodium hydroxide (2.0 grams/ ml H O) to make the reaction mixture slightly alkaline, that is, a pH of about 8 to 9.

After stripping water and dimethyl ketone, the cis diol (VI) was distilled under reduced pressure of 0.1 mm Hg at 120C.

EXAMPLE 6 3,4Bis(Hydroxymethyl)Furan lsopropylidene Ketal (VII) (Vll) 640 Grams (5 moles) of the diol, represented by formula (ll and 1560 grams l5 moles) of 2,2-dimethoxypropane were placed in a beaker and mixed with a magnetic stirrer. After the mixing, 2.0 grams of p-toluenesulfonic acid monohydrate were added. Instantly the reaction mixture became clear and the temperature dropped from 2 1 to l6C. Gas liquid chromatographic analysis indicated completion of the reaction. Immediately, the methanol and the excess dimethoxypropane were removed in a vacuum rotary evaporator at a bath temperature of 40 to 45C. and the ketal represented by formula (VII) was obtained.

The ketal, represented by formula (VII), is very unstable in solid state, and it is imperative to dissolve it in benzene immediately after the removal of methanol and the excess dimethoxypropane.

The ketal, represented by formula (VII) (from Example 6 theoretically 860 grams) was dissolved in 700 ml benzene and placed in a gallon autoclave. Standard Ni catalyst (23% Ni) 225 grams in 300 ml benzene and 1 gram sodium methoxide were added and the ketal, represented by formula (VII) was hydrogenated at 125C. and 1 100 psig (H for 4.5 hours. After completion of the hydrogenation, the catalyst was filtered and most of the benzene was distilled. Ketal (IV) was characterized by gas liquid chromatography and without further purification hydrolyzed to the cis diol, represented by formula (VI). Hydrolysis of the ketal, represented by formula (IV), to cis-3,4-bis( hydroxymethyl)- tetrahydrofuran is accomplished by the method of Example 5.

EXAMPLE 8 cis-3 ,4-Bis(Tosyloxymethyl )Tetrahydrofuran (VIII (VIII) cis To a three-neck flask equipped with a thermometer, reflux condenser, mechanical stirrer, and dropping funnel were added 528.64 grams (4.0 moles) of the cis diol, represented by formula (VI), and 500 ml pyridine; and the mixture was cooled to to 5C. A solution of 1557 grams (8 moles) of p-toluenesulfonyl chloride in 1300 ml pyridine was added slowly through the dropping funnel. The temperature during the addition was kept below 10C. After the addition of ptoluenesulfonyl chloride, the reaction mixture was stirred for 2 to 3 hours and then let stand at room temperature overnight.

The reaction mixture was poured over ice-water and stirred for 30 minutes; then the aqueous layer was decanted. The product was further purified by washing with distilled water.

EXAMPLE 9 cis-trans 3 .4-Bis(Tosyloxymethyl )Tetrahydrofuran (XIX) In a three-neck flask equipped with a thermometer, reflux condenser, mechanical stirrer, and dropping funnel were placed 323 grams (2.45 moles) of cis-trans 3,4-bis(hydroxymethyl) tetrahydrofuran, represented by formula (III), and 350 ml pyridine, and the mixture was cooled to 0 to 5C. A solution of 953 grams (4.89 moles) p-toluenesulfonyl chloride (98%) in 700 ml of pyridine was added slowly through the dropping funnel. After the addition of p-toluenesulfonyl chloride, the reaction mixture was stirred for 2 to 3 hours and then let stand at room temperature overnight. The reaction mixture was poured over ice-water with rapid stirring. After stirring for 30 minutes, the product was a solid and the aqueous layer was decanted. The product cistrans 3,4-bis(tosyloxymethyl)tetrahydrofuran, represented by formulas (XIX), was washed many times with water and dried.

All of the compounds within the scope of the present invention, represented by formula (a) above, can be prepared in accordance with the principles and processes illustrated in the following Examples 10 to 43, with particular reference to types of reactions, types of reactants, ratios of reactants, reaction solvents, reaction times, temperatures, and other conditions cited. The compounds represented by formula (a) above where R is an acyl radical or substituted acyl radical are readily prepared by reacting hexahydro-lH-furo(3,4- c)pyrrole with an equal mole portion of an acyl chloride corresponding to the R substituent desired in a suitable solvent, such as an aqueous sodium hydroxide solution or benzene as illustrated in the following Examples 14 to 35 and 43. When substituent R of the compounds respresented by formula (a) above is other than acyl, the subject compounds can be prepared by reacting the ditosylate compound represented by formulas (VIII) or (XIX) with an excess of an amine corresponding to the R substituent desired in a suitable solvent, such as triethylene glycol dimethyl ether as illustrated in Examples 36 to 42.

(Vlll) cis In a three-neck flask equipped with a mechanical stirrer, thermometer, and reflux condenser were placed 484.5 grams (1.1 moles) of the ditosylate, represented by formula (VIII), 353.6 grams (3.3 moles) of benzylamine and 500 ml of Ansul 141 (diethylene glycol dimethyl ether). The mixture was heated to 140C., at which point the reaction became rather vigorous. The heating mantle was removed and the reaction mixture was cooled with cold water until the vigorous reaction subsided; then the reaction mixture was heated at 160C. for 2.5 hours. The mixture was then cooled to 30 to 40C. and a methanolic sodium hydroxide solution (88 grams NaOH in 400 ml CH OH) was added while stirring. Methanol to 200 ml) should be added prior to the sodium hydroxide addition if the reaction mixture becomes too viscous when cooled to 30 to 40C.

After stirring for 0.5 hour, the sodium tosylate was filtered and washed with ethyl ether/methanol (95:5). The filtrate and ether/methanol washings were combined and the organic solvents stripped under reduced pressure. During the stripping of solvents, additional salt precipitated and this was filtered and washed with ether/methanol. The solvents from the combined filtrates were stripped and product represented by formula (IX) distilled at 95 to C./0.l5 mm Hg.

The hydrochloride salt was formed by dissolving product (IX) in ether and passing in anhydrous HCl gas. The HCl salt of the product, represented by formula (IX), has a melting point of 182 to 183C.

Analysis (C H NOCL). Calculated: C, 65.12%; H, 7.57%; N, 5.84%; CI, 14.79%. Found: C, 65.12%; H, 7.55%; N, 5.86%; CI, 14.74%.

EXAMPLE 1 1 Hexahydro-1H-Furo(3,4c)Pyrrole (X) Prepared by Debenzylation of S-Benzyl-Hexahydro-1H-Furo( 3,4-c)Pyrrole S-Benzyl-hexahydro- 1 H-furo( 3,4-c )pyrrole, illustrated by formula (IX) (502 grams, 2.47 moles), Palladium on carbon (30 grams), and 675 ml of absolute ethanol were placed in a one-gallon autoclave. Hydrogen was added and the mixture was heated at 70-75C. for 4 hours at 70 psig. The reaction was monitored by the absorption of H and gas liquid chromatographic analysis. The catalyst was filtered over Super Cel (diatomaceous earth) and the ethanol was stripped at atmospheric pressure. The product (X), a clear colorless liquid, distilled at 182 to 188C.

Analysis (C H NO). Calculated: C, 63.66%; H, 9.82%; N, 12.37%. Found: C, 63.55%; H, 9.78%; N, 12.14%.

EXAMPLE 12 Reaction of cis-3,4-Bis (Tosyloxymethyl)Tetrahydrofuran and Ammonia cis-3 ,4-Bis(tosyloxymethy1)tetrahydrofuran 190 grams), illustrated by formula (V111), and liquid ammo nia (100 grams) in a 1 liter of absolute ethanol were heated at 150C. for 2 hours at 600 psig in a one-gallon autoclave. The reaction mixture was cooled, treated with a methanolic sodium hydroxide solution (34.5 grams NaOH in 200 ml CH OH), filtered, and the solid washed with diethyl ether. The filtrate and ethereal washings were combined and the solvents were stripped at atmospheric pressure. Additional sodium p-toluenesulfonate, which precipitated when most of the solvents were distilled, was removed by filtration, and the stripping was continued. The product (X) was distilled at atmospheric pressure at 182 to 188C.

EXAMPLE 13 Hexahydrol H-Furo( 3 ,4-c )Pyrrole Hydrochloride Hexahydro-lH-furo(3,4-pyrrole (1 1.3 grams, 0.1 mole) was dissolved in 200 ml diethyl ether and anhydrous HCl gas passed through the solution. The salts were filtered and washed with ether.

Analysis (C H NOCL). Calculated: C, 48.16%; H, 8.09%; N, 9.36%; Cl, 23.70%. Found: C, 48.08%; H, 7.68%; N, 9.16%; Cl, 23.70%.

Phenylacetyl chloride 15.46 grams, 0.1 mole), Aldrich Chemical Co., Inc., Milwaukee, Wis., was slowly added to a mixture of hexahydro-1H-furo(3,4- c)pyrrole hydrochloride (14.96 grams, 0.1 mole) and 300 ml aqueous sodium hydroxide (10.0 grams, 0.25 mole NaOH in water) at 10C. After the phenylacetyl chloride addition, the ice bath was removed and the reaction mixture was stirred for 1.5 hours. The reaction mixture was extracted with diethyl ether (4 X 200 ml) and the extract treated with DARCO G-6O (activated carbon). Removal of diethyl ether gave S-phenylacetylhexahydro-1H-furo(3,4-c)pyrrole (19.35 grams) a clear viscous liquid which solidified on cooling. This product was recrystallized from diethyl ether and had a melting point of 47.5 to 485C.

Analysis for C H NO Calculated: C, 72.70%; H, 7.41%; N, 6.06%. Found: C, 72.76%; H, 7.60%; N, 6.02%.

EXAMPLE 1 5 5 -Benzoyl-Hexahydro- 1 H- F uro( 3 ,4c )Pyrrole Benzoyl chloride (14.06 grams, 0.1 mole), Aldrich Chemical Co., 1nc., Milwaukee, Wis., was slowly added to a mixture of [compound (X)] hexahydrol H- furo(3,4-c)pyrrole (1 1.3 grams, 0.1 mole) and sodium hydroxide 10 grams) in 300 ml of water at 10C. After the addition of benzoyl chloride, the reaction mixture was stirred at room temperature for 2 to 3 hours and the product was extracted with diethyl ether (4 X 200 ml). Removal of the ether gave the product 5-benzoylhexahydro-lH-furo(3,4-c)pyrrole, represented by formula (X1), as a clear viscous liquid which solidified on standing. The product was crystallized from diethyl ether and had a melting point of 47 to 48C.

Analysis for C,;,H, NO Calculated: C, 71.90%; H, 6.92%; N, 6.46%. Found: C, 71.92%; H, 6.90%; N, 6.53%.

Using the procedure of Example 15, 0.1 mole por tions of hexahydro-1H-furo(3,4-c)pyrrole [compound (X)] were reacted with 0.1 mole portions of other acyl chlorides listed in Table 1 below in aqueous sodium hydroxide solution to produce S-acylhexahydro-lH- furo(3,4-c )pyrroles corresponding to the acyl radicals listed under the heading R in Table l.

S-Acyl-Hcxahydro- 1 HFuro( 3 .4- c )Pyrrolcs O ANALYSIS Found Calculated Ex. C1. F CLF No. Acyl Chlorldcs R M.P. C. C H N or S C H N or S 16 hcnzoylchloridc (I? 4748 7192 6.90 6.53 71.90 6.92 6.46

C,;H -,C- 11 17 l-naphthtiylchloridc 79-805 76.41 6.32 5.18 76.58 6.20 5.24

(Eastman Kodak ($0., Rochester. N.Y.)

l8 p-chlorobcnzoylchloride O Viscous 62.04 5.42 5.53 14.19 62.03 5.61 5.57 14.09

(Aldrich Chemical Co., 11 Liquid (C1) lnc., Milwaukee, Wis.) Cl

I 0 19 m-chlorobenzoylchloridc 1| Viscous 61.89 5.59 5.46 14.01 62.03 5.61 5.57 14.09

(Aldrich Chemical Co., C Liquid (Cl) lnc.)

20 o-chlorobenzoylchloride O Viscous 61.93 5.67 5.45 14.28 62.03 5.61 5.57 14.09

(Aldrich Chemical Co. 11 Liquid (1 Inc.) C

21 m-trifluoromethylbenzoyl O Viscous 58.88 4.91 5.17 20.17 58.94 4.95 4.91 19.88

chloride (Pierce Chemical 1| Liquid (F) (F) Co. Rockford, Illinois) C 3 22 cinnamoyl chloride 0 1305-131 74.10 7.17 5.72 74.04 7.04 5.76

(Aldrich Chemical Co., 11 Inc.) C H CH=CHC 0 ll 23 o-chlorophenylacetyl -CH C 84.5- 63.54 5.31 13.51 63.27 6.07 5.27 13.34

5.13 chloride L 0 24 m-chlorophenylacetyl ll 85.5-86.5 63.30 5.87 5.37 13.43 63.27 6.07 5.27 13.34

chloride CH C 0 25 p-chlorophenylacetyl 11 995- 63.16 6.27 5.25 13.46 63.27 6.07 5.27 13.34

chloride CL CH C- 26 hcxahydrobenzoyl chloride 0 48.5-49.5 69.83 9.52 6.21 69.92 9.48 6.27

(K&K Laboratories, l1 Plainvicw N.Y.) C

O 27 propionylchloridc l1 B.P.ll8/ 64.22 8.67 8.39 63.88 8.93 8.27

(Aldrich Chemical C H C 0.05 mm Co. Inc.) Hg

28 m-mcthoxybenzoylchloridc C- Viscous 68.14 6.96 5.70 67.99 6.93 5.66

Liquid a 1 29 Z-Ihcnoylchloridc C -171 59.10 5.80 6.16 14.26 59.17 5.87 6.27 14.36

(.LT. Baker Chemical Co.. Phillipsburg, NJ.)

Product was purified by column chromatography (silica gel-ether). Product was distilled. Product was distillcd at INN-210C. bath temperature at 0.150 mm Hg and pun'ficd by column chromatography (silica gel-ether).

15 16 EXAMPLE 30 Cl S-Nicotinoyl-Hexahydrol H-Furo( 3,4-c )Pyrrole 0 H OCH. .CC1

CCH O Cl H s o i O (X) (XIV) (xv (X) (X11) C p-Chlorophenoxyacetyl chloride, represented by for- (Xm) mula (XIV), (0.0813 mole, 16.65 grams) was slowly added to a mixture of heXahydro-lH-furo(3,4- 5 c)pyrrole, represented by formula (X), (0.0813 mole, 9.20 grams),' and triethylamine (0.0813 mole, 8.23

Nicotinoyl chloride hydrochloride, represented by grams) in 160 ml benzene at 10C. The reaction formula (X11), (0.1 mole, 17.81 grams) was sl y ure was stirred for 18 hours while warming to room added to a mixture of hexahydro-lH-furo(3,4- temperature cmyrrole' reprsemed 8 f0rmula(x) mole 20 The triethylamine hydrochloride salt that formed grams) and methymmme E m during the reaction was filtered and washed with ben- 160 ml of benzene at 15C. The reaction mixture was Zena The benzene wash and filtrate were combined stirred for l .5 hours at 15 C. and then left overnight at and Stripped f benzene i a rotary evaporator which room temperature The HC] [Salt of Fnethylamme was effected crystallization. Recrystallization of the prodmterd and the Salt was washed benzene The 25 uct from absolute ethanoLfiltration and drying yielded washings were combined with the filtrate and benzene fine white Crystals of was stripped under vacuum. The product, 5-nicotinoylchlorophenoxyacetyl)hexahydro 1H fum(3,4 heXahYdrO'IH'fumGA'C W @Presemed c)pyrrole having a melting point of lO9.5 to l 10C. mula (X111), light yellow VlSCOUSdlqLHd, was purified by Analysis for CMHIGOBNCL Calculated. C, 5968170; H column chromatography (Alumina-eluted with methyl 573%; N, 497%; C], Found. C 59 51%; H, flcetatelg 5.79%; N, 494%; ci, 12.79%.

Analysls for CIZHHOZN2- Calculated: 66-03%; Using the procedure of Examples 30 and 31, 0.1 Found: 658.3%; 640%; mole portions of hexahydro-lH-furo(3,4-c)pyrrole 1285 were reacted with 0.1 mole portions of the acyl chlorides, listed in Table 11 below, in benzene and triethyl- EXAMPLE 31 amine (0.1 mole) as a base to produce the 5'acyl- S-(p-Chlorophenoxyacetyl)-Hexahydro-lH-Furo(3,4- heXahydro-lH-furo(3,4-c)pyrroles corresponding to c)Pyrro1e the acyl radicals listed under the heading R in Table 11.

TABLE 11 S-Acyl-Hexahydrol H-Furo( 3,4-c )Pyrroles O N R ANALYSIS Ex. Found Calculated No. Acyl Chloridcs R M.P. or B.P. C H N Cl C H N Cl 32 o-acctoxybenzoyl O B.P. 177-178 65.31 6.18 5.12 65.44 6.23 5,04

chloride c7002 mrn OCCH 101 33 2.4.6-trimclhyl- Viscous 74.17 8.07 5.31 74.10 8.16 5.40

hcnznyl CH QQCH, Colorless chloride 3 0 Liquid 4 34 2.6-dimcthylbcnzoyl 3 Fllii'il 73.35 7.81 5.09 73.44 7.81 9.71 4

chloride 0 Yellow Viscous Liquid 4 35 ohydroxybcnzoyl MP. 92-- 6684 6.28 6.10 A 66.93 6.48 6.01 A

chloride 0 915C.

9 35" 3.4-dichlorohcnxoyl c Viscous 54.53 4.87 4.81 14.75 54.57 4.58 4.90 24.78

chloride (lciir Liquid EXAMPLE 36 S-Allyl-l-lcxahydro- 1 H-Furo( 3 ,4-c)Pyrrole the reaction mixture was concentrated under aspirator pressure, 300 ml of diethyl ether was added and the sodium tosylate was filtered. The product 5-(2- hydroxyethyl )-hexahydrol 1-1-furo( 3 ,4-c )pyrrole was 5 distilled at 137 to l41C./6.0 to 6.9 mm Hg.

Analysis (C H NO Calculated: C, 61.12%; H, ----cll,oso.c.,ll,cl-l., 9.62%; N, 8.91%. Found: C, 61.05%; H, 9.64%; N, 0 CH =CHCH NH 8.87%.

--CH OSO- iC.,H..CH,,p l0

EXAMPLE 38 (V111) cls F S-Phenethyl-Hexahydrol H-Furo( 3,4-c Pyrrole Q N CH CH=CH Hydrochloride l5 Phenethylamlne (0.15 mole, 18.2 grams) was reacted (Xvm) with a mixture of the cis and trans isomers of 3,4-

bis(tosyloxymethyl')tetrahydrofuran, represented by formulas (XIX), (0.05 mole, 22.0 grams) in 60 ml triethylene glycol dimethyl ether at 185C. for 3 hours. The reaction mixture was cooled to room temperature Allylamine (0.6 mole, 35 grams) and the ditosylate, and neutralized with 75 ml methanolic sodium hydroxrepresented by formula (V111), (0.2 mole, 88.0 grams) ide solution (0.10 mole, 4.0 grams). After the reaction in 300 ml of absolute ethanol were heated for 2 hours mixture was concentrated under aspirator pressure, in an autoclave at 150C. and 200 to 210 psig pressure. 150 ml diethyl ether was added and sodium tosylate The reaction mixture was cooled and treated with etha- (18.5 g was filteredaC um distillation of the nolic sodium hydroxide solution (13 grams NaOH) ltrate gave S-phenethyl-hexahydro-lH- The sodium tosylate was filtered and the excess allyli -)Py" grams, -1 l 1 Into 1 amine and ethanol were stripped from the filtrate at 31- mm y y 1 mospheric pressure. The product 5-allyl-hexahydro- P was dlssolved 700 ml allhydrous dlethyl lH-furo(3,4-c)pyrrole distilled as a colorless liquid at ether and anhydroqs hydrogen chloflde was bubbled 56 C /O-5 mm of mercury pressure 7 through the solution. The resultlng S-phenethylhexahydro-lH-furo(3,4-c)pyrrole hydrochloride was Analysis (C9H15ON)- Calculated: 70507"; filtered, washed with ether, and dried. The product ob- 9.86%; N, 9.13%. Found: C, 70.47%, H, N, tained had a melting point of 7 0 to 1770C. 899% 35 Analysis (C 1-1 NOC1). Calculated: c, 66.23%; H, EXAA/[PLE 37 7.94%; N, 5.52%; Cl, 13.97%. Found: C, 66.38%; H, 5-(2-Hydroxyethyl)-HexahydrolH-Furo(3,4- 7

c)pyn.ole Uslng the procedure of Example 38, 0.05 mole portions of the cis-trans ditosylate, represented by formu- Aminoethanol (0.8 mole, 48.9 grams) was reacted las (XIX), were reacted with 0.15 mole portions of with cis-trans 3,4-bis(tosyloxymethyl)tetrahydrofuran, amines listed in Table 111 below to produce various represented by formulas (XIX), (0.2 mole, 88.1 grams) compounds of the present invention corresponding to in ml of triethylene glycol dimethyl ether at C. the alicyclic, aralkyl, and aryl radicals listed under the for 3 hours. The reaction mixture was cooled to room heading R in Table 111. Obviously, the same type comtemperature and neutralized with 150 ml of methanolic 45 pounds can also be prepared directly from the cis ditosodium hydroxide solution (16 grams NaOl-l). After sylate compound (V111).

TABLE 111 S-Aralkyl, Aryl, and Alicyclic-Hexahydro-lH-Furo(3,4-c)Pyrrole Hydrochlorides o N -R HCl 3 ANALYSIS .Ex. M.P. C. Found 71 Calculated 7:

No. Amine Reactant R HCl Salt C H N Cl C H N C1 39 p-chlorophenethylpC1C H, CH CH 174-175 58.52 6.57 4.76 24.50 58.34 6.64 4.86 24.61

amine 40 benzylaminc C,,H,,CH 182183 65.12 7.55 5.86 14.74 65.12 7.57 5.84 14.79 41 cyclohexylamine O- 247-249 6 .32 9.80 6.05 15.49 62.18 9.57 6.04 15.30 42 aniline C,,H 152.5- 63.87 22 63.85 7.15 6.21 15.71

EXAMPLE 43 5-(Benzenesulfonyl)-Hcxahydro-1H-Furo(3,4- c)Pyrrole P ridine H SO Cl :5:0 o

(XVII) Benzenesulfonyl chloride (0.05 mole, 8.83 grams) dissolved in 15 ml pyridine was slowly added to a mixture of hexahydrolH-furo(3,4-c)pyrrole, represented by formula (X), (0.05 mole, 5.66 grams) in 10 ml of pyridine at C. The reaction mixture was stirred for 2 hours at 5C. and then for 16 hours while warming to room temperature.

The reaction mixture was poured over an ice-water mixture which effected a precipitate. The crude product was filtered and washed with water to remove excess pyridine and pyridine hydrochloride. The product 5-( benzenesulfonyl )-hexahydrol H-furo( 3,4-c )pyrrole was recrystallized from methanol, obtaining upon filtration and drying, white crystals having a melting point of 104.5 to l05.5C.

Analysis of (C H O NS). Calculated: C, 56.89%; H, 5.97%; N, 5.53%; S, 12.66%. Found: C, 57.04%; H, 5.91%; N, 5.56%; S, 12.76%.

Terephthaloyl chloride (7.6 grams, 0.038 mole) was added to a mixture of hexahydro-lH-furo(3,4- c)pyrrole (8.5 grams, 0.075 mole), represented by formula (X) and triethylamine (7.6 grams, 0.075 mole) in 50 ml benzene at 6C. The reaction mixture was stirred for 10 minutes and then allowed to warm at room temperature when the reaction became exothermic (temperature rose to 60C.). The reaction mixture was then cooled and the triethylamine tered. By adding ethyl ether to the filtrate (benzene), the product was precipitated as a white crystalline material. Finally, the product, 5,5'-terephthaloyl-bis- [hexahydro-lH-furo(3,4-c)pyrrole], was crystallized from benzene-ether (1:1 solution. The resulting dried product had a melting point of l91.5 to 193.0C.

\nalysis for C H O N Calcu ated: C, 67.40%; H.

. hydrochloride was fil- 6.79%; N, 7.86%. Found: C, 67.83%; H, 6.84%; N, 7.78%.

EXAMPLE 45 5 ,5 '-Adipyl-Bis- Hexahydro- 1 H-Furo( 3 ,4c Pyrrole] Adipyl chloride 12.81 grams, 0.07 mole) was added to a mixture of hexahydro-lH-furo(3,4-c)pyrrole (X) 15.84 grams, 0.14 mole) and triethylamine 14.20 grams, 0.14 mole) in 200 ml benzene at 10C. The reaction mixture was stirred for 45 minutes at 10 to 15C. and for 2 hours at room temperature. The triethylamine hydrochloride was filtered and the filtrate was treated with Darco (G 60) activated carbon. By adding ethyl ether to the filtrate (benzene) the product was precipitated as a white crystalline material. Finally, the product, 5 ,5 '-adipyl-bishexahydrol H-furo( 3 ,4- c)pyrrole] was crystallized from benzene-ether (1:1) solution (m.p. 96 to 975C).

Analysis for C, H O N Calculated: C, 64.28%; H, 8.39%; N, 8.26%. Found: C, 64.15%; H, 8.12%; N, 8.1 1%.

EXAMPLE 46 S-Butyl-l-lexahydro- 1H-Furo( 3 ,4-c )Pyrrole Butylamine (0.416 mole, 30.4 grams) and the ditosylate, represented by formula (V111) above, (0.14 mole, 61 grams) in 300 ml of absolute ethanol were heated for 2 hours in an autoclave at 150C. and 200-210 psig pressure. The reaction mixture was cooled and treated with ethanolic sodium hydroxide solution (1 1.3 grams NaOH). The sodium tosylate was then filtered and the excess butylamine and ethanol were stripped at atmospheric pressure. The product, S-butyl-hexahydro-lH- furo(3,4-c)pyrrole distilled as a colorless liquid at 81 to 85C./3.5 mm of mercury pressure.

Analysis (C H ON). Calculated: C, 70,96%; H, 11.31%; N, 8.27%. Found: C, 71.08%; H, 11.13%; N, 8.28%.

Obviously, other 5-alkyl-hexahydro-lH-furo(3,4- c)pyrrole products can be prepared by the method of Example 45 by mere substitution of the alkylamine.

The physiologically or phannacologically acceptable acid addition salts of the present pyrrole compounds are included within this invention. These acid addition salts are prepared by known processes, such as illustrated in several of the preceding examples, which involve reacting a free base compound of the present invention with an appropriate acid in a suitable solvent, for example, diethyl ether or ethyl alcohol. For example, among the mineral acids that can be used to prepare the subject acid addition salts are hydrochloric acid, hydrobromic acid, sulfuric acid, and phosphoric acid. Suitable organic acids that can be used to prepare the subject acid addition salts are, for example, acetic acid, methane-sulfonic acid, propionic acid, maleic acid, fumaric acid, tartaric acid, citric acid, and benzoic acid.

As shown in the above examples, the compounds of the present invention can be suitably purified by conventional methods, for example, by distillation, crystallization, or chromatography as indicated.

The acyl chloride reactants used to prepare the products of the present invention represented by formula (a) hereinabove where R is an acyl radical or substituted acyl radical can readily be prepared from their corresponding acid compound by reaction with an excess of a suitable agent, such as thionyl chloride, or phosphorus halides, such as PCL, and PCl All of the acyl chloride reactants required for the preparation of the subject substituted compounds can be prepared by suitably using one of the well-known methods illustrated in Examples A to K. However, most of the acyl chlorides needed to prepare the subject compounds are commercially available.

EXAMPLE A p-Chlorophenoxyacetyl Chloride EXAMPLE F m-Methoxybenzoyl Chloride A mixture of 50 grams of m-methoxybenzoic acid and 125 ml of thionyl chloride was heated for 3 hours at 70C. The excess thionyl chloride was stripped under vacuum to yield the desired acyl chloride product. The product Z-methoxybenzoyl chloride distilled at 77 to 78C./l to 2 mm Hg.

Using the procedure of Example F, a molar excess of thionyl chloride was reacted with portions of the acid compounds listed in Table V to make the acyl chloride products indicated. The molar ratio of thionyl chloride to acid reactant used, for example, can be withinthe range of 2:1 to 4:1. The exact amount of thionyl chloride used is not critical so long as it is in substantial molar excess in relation to the acid reactant. After the desired reaction is completed, the excess thionyl chloride is easily removed by stripping under vacuum.

TABLE V Example Acid Reactants Acyl Chloride Products Boiling Point O o-chlorophenylacetic acid o-chlorophenylacetyl chloride H m-chlorophcnylacetic acid m-chlorophenylacetyl chloride l p-chlorophenylacetic acid p-chlorophenylacetyl chloride 85C./l.0 mm Hg cl c| 3O EXAMPLE J Salicylyl Chloride SOCI CGHB 2 TI A mixture of 10 grams salicylic acid, 7 ml of thionyl chloride, and 0.02 ram of aluminum chloride was OCH COOH OCH-2 g Thionyl chloride (0.431 mole, 51.26 grams) was slowly added to p-chlorophenoxyacetic acid (0.287 mole, 53.5 grams) in 160 ml of benzene at room temperature. The reaction mixture was refluxed for 18 hours. The excess thionyl chloride and benzene were stripped from reaction mixture under vacuum (aspirator) and the residue p-chlorophenoxyacetyl chloride was distilled at 70C./0.05 mm Hg.

Using the procedure of Example A, a molar excess of thionyl chloride was reacted with portions of the acid compounds listed in Table IV to make the named acyl chloride products indicated. The molar ratio of thionyl chloride to acid reactant used, for example, can be within the range of 2:1 to 4: l. The exact amount of thionyl chloride used is not critical so long as it is in substantial molar excess in relation to the acid reactant. After the desired reaction is completed, the excess thionyl chloride is easily removed by stripping under vacuum. The boiling points of the various acyl chloride products prepared are listed next to these products in Table IV.

heated at 40 to 45C. for 1 /2 hours. The excess thionyl chloride was removed in vacuum and the salicylyl chloride reaction product can be used without further purification.

EXAMPLE K Nicotinoyl Chloride-Hydrochloride A mixture of grams of nicotinic acid and ml of thionyl chloride was heated at 55 to 65C. for 3% hours. The excess thionyl chloride was removed in vacuum and the nicotinoyl chloride-hydrochloride reaction product can be used without further purification.

Evaluation in laboratory animals indicates that the present compounds possess analgesic and/or antiinflammatory activity when administered in a therapeutically effective amount. The effectiveness and dosage required vary, as is customary in this art, with the species being treated, particular disorder being treated, weight of the animal, and the route of administration. In accordance with the present invention, the subject compounds are administered at doses from about 0.5 milligram to 400 milligrams per kilogram body weight TABLE IV Example Acid Reactants Acyl Chloride Products Boiling Point B 2,4,6,-trimethylhenzoic acid 2,4,6-trimethylbenzoyl chloride 48C./0.05 mm Hg C m-mcthoxybenzoic acid m-methoxybenzoyl chloride 59C./0.06 mm Hg D 2.6-dimethylbenzoic acid 2,6-dimethylbenzoyl chloride 38C./0.05 mm Hg E o-ucetoxyhenzoic acid o-acetoxybenzoyl chloride 75.5-76C./0.04

1 to 4 times a day. A more preferred dose is from about 1.0 milligram to 300 milligrams per kilogram body weight 1 to 4 times a day.

The analgesic and anti-inflammatory properties of the novel compounds of the present invention were determined by several different testing procedures. Among the tests used are, for example, the Rat 1n flamed Paw Pressure Test, the Mouse Acetylcholine Writhing Test, and the Rat Carrageenan Edema Test, which can be carried out as follows:

Rat lnflamed Paw Pressure Test (Analgesic Test) Non-fasted albino rats in the weight range of 160 to 180 grams are used. The experimental drugs are administered orally 10 ml/kg volume). Immediately after the administration, 0.1 ml of a 1% sodium carrageenan (Marine Colloids, lnc., Springfield, NJ.) in a sterile 0.9% aqueous solution of sodium chloride is injected into the subplantar region of the right hind paw. At a specific time post drug administration, the animals right hind paw is placed between two plastic-grooved discs which are compressed by air pressure, and the amount of pressure required to induce vocalization and/or biting of the apparatus is recorded. The average pressure requirements for a drug-treated group of 6 an imals is compared to that of a control group which receive 0.9% saline in place of the drug. The percent change of the test group from the control group is calculated.

-Benzoyl-hexahydro-1H-furo(3,4-c)pyrrole when evaluated in this test had an ED of 70 mg/kg body weight. Acetylsalicylic acid in the same test had an ED of 1,500 mg/kg body weight, and codeine sulfate had an ED of 167 mg/kg body weight. 5-(p- Chlorophenethyl )-hexahydro- 1 H-furo( 3 ,4-c) pyrrole when evaluated in this test had an ED of 72 mg/kg body weight.

Mouse Acetylcholine writhing Test (Analgesic Test) Female albino mice weighing 18 to 25 grams are administered the test drugs orally ml/kg volume). One-half hour after administration of the test drug, acetylcholine bromide (l 1.0 ml/kg) is administered intraperitoneally (10 ml/kg) and the time to writhing recorded. The observation period extended for 10 minutes. Control animals dosed with 0.9% saline (10 ml/kg) are tested simultaneously. The percent inhibition of writhing is calculated from the number that did not writhe in 2 minutes post injection of the acetylcholine bromide.

S-Benzoyl-hexahydro-1H-furo(3,4-c) pyrrole when evaluated in this test had an ED of 210 mg/kg body weight. Acetylsalicylic acid in the same test had an ED of 150 mg/kg body weight and codeine sulfate had an ED of 46 mg/kg body weight. 5-(p- Chlorophenethyl )-hexahydrol H-furo( 3 ,4-c )pyrrole when evaluated in this test had an ED of 72 mg/kg body weight.

Rat Carrageenan Edema Test (Anti-inflammatory Test) Non-fasted albino rats in the weight range of 160 to 180 grams are used. The test drugs are administered orally. Immediately following administration of the drug, 01 ml of a 1% carrageenan suspension (Marine Colloids, lnc., Springfield, NJ.) in a sterile 0.9% aqueous solution of sodium chloride is injected into the sub plantar area of the right hind paw and the foot volume measured by volume displacement. The foot volume is measured again at 4 hours post injection of the drug and the percent change in volume when compared to a control group receiving 0.9% saline instead of the drug is calculated.

5Benzoyl-hexahydro-1H-furo(3 ,4-c )pyrrole when evaluated in this test had an ED of 690 mg/kg body weight. Acetylsalicylic acid in this test had an ED of 1 10 mg/kg body weight. Codeine sulfate exhibited no activity in this test. S-(p-Chlorophenethyl)-hexahydro- 1Hfuro(3,4-c)pyrrole when evaluated in this test had an ED of 600 mg/kg body weight.

The compounds 5-hexahydrobenzoyl-hexahydro-1H- furo (3,4-c)pyrrole, 5-(o-acetoxybenzoyl)-hexanhydro-lH-furo(3,4-c) pyrrole and 5-benzyl-hexahydrolH-furo(3,4-c)pyrrole at 300 mg/kg body weight gave 20% inhibition against edema caused by the injection of sodium carrageenan under the conditions of this anti-inflammatory test.

The designation ED is used hereinabove to designate a dose level which showed significant activity in 50% of the animals tested.

As the compounds within the scope of this invention are effective upon oral administration, they can be compounded into any suitable oral dosage form, such as in tablet, capsule, syrup, elixir, suspension or other solid or liquid forms that can be prepared by procedures well known in the art. Thus, the subject novel compounds can be mixed with a suitable diluent, such as lactose or kaolin, and encapsulated; or they can be combined with suitable binding agents and expanding agents and compressed into tablets. In addition, a liquid pharmaceutical may be obtained by dissolving, dispersing, or suspending novel compounds of this invention with a suitable flavored liquid. The present compounds are also considered active upon parenteral and rectal administration.

Examples of formulations for preparing tablets, capsules, liquids, parenterals and suppositories containing the novel compounds of the present invention are described below. Obviously, it will be recognized by one skilled in the present art that the following formulations represent only one method of preparing such pharmaceutical compositions and obviously the size of the tablet or capsule or the strength of the dosage form may be suitably varied in order to satisfy the particular requirements, such as dosage level indicated. For example, each dosage unit may conveniently contain from about 15 milligrams to 5,000 milliggrams of the active ingredient admixed with a diluent amount of a pharmaceutically acceptable carrier. Any of the well-known suitable pharmaceutical carriers can be used to prepare acceptable dosage forms so as to provide an effective amount or therapeutically effective amount of the compound to be administered.

Tablet Containing mg of Combine'all ingredients, mix, and then compress into slugs. The slugs should then be ground to form granules that will pass through a l4 to T6 mesh screen; The granules may then be recompressed into tablets using a suitable compression mold to form tablets, each weighing 280. mg.

Capsule Containing 200 mg of S-(m-Chlorophcnylacctyl )Hexahydro- 1 H-Furo( 3,4-c )Pyrrole m-Chlorophcnylacetyl )Hcxahydrol H-Furo( 3,4-c )Pyrrolc Powdered Lactose D.T.D. Capsules No. 1000 200 mg 100 mg Mix the ingredients so as to evenly distribute the active ingredient throughout the lactose. Pack the powder into a No. 1 empty gelatin capsule.

Suspension Containing 50 mg per 5 cc of S-Benzoyl-Hexahydro- I H-Furo( 3,4-c )Pyrrole S-Benzoyl-Hexahydrol HFuro (3,4.-c) Pyrrole 10 grams Tragacanth 50 grams Amaranth 10 grams Syrup Wild Cherry 60 ml Distilled Water q.s. 1000 ml Hydrate the tragacanth with sufficient water to form a smooth paste and to this add the 5-benzoyl-hexahydro-lH-furo (3,4-c)pyrrole, followed by the amaranth which has been previously dissolved in water. Then add the syrup of wild cherry and add distilled water to make 1000 ml.

lnjectable Containing 5 mg of S-Nicontinoyl-Hexahydrol H-Furo( 3 ,4c) Pyrrole Per Milliliter Suitable for Intramuscular, lntraperitoneal or Subcutaneous injection S-Nicotinoyl-Hexahydro-l H- Furo( 3,4-c)Pyrrole 5.0 grams Chlorobutanol 3.0 grams Propylene Glycol 20.0 ml Water for Injection q.s. 1000.0 ml

Combine the above ingredients, clarify by filtration, fill into vials, seal, and autoclave.

Suppository Containing 200 mg of S-Phenethyl- Hexahydro-lH-Furo(3,4-c) Pyrrole Hydrochloride S-Phenethyl-hexahydrol H- Furo( 3,4-c)Pyrrole Cocoa Butter Make of Such No. 100

0.2 gram 1 .8 grams wherein R is a radical selected from the groupconsisting of hydrogen; alkyl'ene(C to C dicarbonyl hex ahydro-lH-furo (3,4'-c)pyrrolc; phenylene dicarbonyl hexahydro-lH-furo (3,4-c)pyrrole; phenyl; phenylacetyl; monoalkoxy (C to C substituted benzoyl; phenylalkyl where the alkyl constituent thereof contains from 1 to' 4 carbon atoms; alkenyl (C and C mono-, di-, or tri-halogen substituted 'phenylalkyl where the alkyl group contains from 1 to 4 carbon atoms and the halogen is substituted on the phenyl ring; benzoyl; mono'-, di-, or tri-halogen substituted benzoyl; mono-, di-, or tri-alkyl (C to C substituted benzoyl; mono-, di-, or tri-halogen substituted phenylalkanoyl wherein the alkanoyl group contains from 2 m4 carbon atoms and the halogen is on the phenyl ring; hexahydrobenzoyl; phenylalkenoyl wherein the alkenoyl group is a lower alkenoyl containing from 3 to 5 carbon atoms; phenylethanoyl; halogen-substituted phenoxyalkanoyl wherein the alkanoyl group contains from 1 to 4 carbon atoms and the phenoxy ring is substituted with from 1 to 3 halogen atoms, alkanoyl (C to C haloalkyl (C to C mono-, di-, or tri-substituted benzoyl wherein the haloalkyl group contains from 1 to 5 halogen atoms; monoor di-hydroxyl substituted alkyl where the alkyl group contains from l to 4 carbon atoms; phenylsulfonyl; monoor di-hydroxyl substituted benzoyl; nicotinoyl; monoor di-alkanoyloxy (C to C substituted benzoyl; thenoyl; cycloalkyl (C to C and the pharmacologically acceptable acid addition salts thereof.

2. A compound of claim 1 wherein R is a radical selected from the group consisting of phenethyl, chlorophenethyl, hydrogen, cyclohexyl, benzoyl, benzyl, chlorobenzoyl, phenylacetyl, chlorophenylacetyl, chlorophenoxyacetyl, propionyl, nicotinoyl, trifluoromethylbenzoyl, dimethylbenzoyl, thenoyl, trimethylbenzoyl, propenyl, hydroxyethyl, benzenesulfonyl, hydroxybenzoyl, cinnamoyl, naphthoyl, and the pharmacologically acceptable acid addition salts thereof.

3. A compound of claim 1 wherein R is a radical selected from the group consisting of hydrogen, 0- acetoxybenzoyl, 2,4,6-trimethylbenzoyl, 2,6- dimethylbenzoyl, o-hydroxybenzoyl, pchlorophenethyl, benzyl, cyclohexyl, phenyl, benzoyl, l-naphthoyl, p-chlorobenzoyl, m-chlorobenzoyl, ochlorobenzoyl, m-trifluoromethylbenzoyl, cinnamoyl, o-chlorophenylacetyl, m-chlorophenylacetyl, pchlorophenylacetyl, hexahydrobenzoyl, propenyl, mmethoxybenzoyl, thenoyl, phenethyl, phenylacetyl, p-chlorophenoxyacetyl, propionyl, nicotinoyl, hydroxyethyl, benzenesulfonyl, and the pharmacologically acceptable acid addition salts thereof.

4. A compound of claim 1 wherein R is a radical selected from the group consisting of benzoyl, naphthoyl, phenacetyl, p-chlorobenzoyl, m-chlorobenzoyl, ochlorobenzoyl, m-trifluoromethylbenzoyl, cinnamoyl, o-chlorophenylacetyl, m-chlorophenylacetyl, pchlorophenylacetyl, p-chlorophenoxyacetyl, propionyl, m-methoxybenzoyl, 2-thenoyl, 2,4,6-trimethylbenzoyl, 2,6-dimethylbenzoyl, 3-nicotinoyl, and ohydroxybenzoyl, and the pharmacologically acceptable acid addition salts thereof.

5. A compound of claim 1 which is S-benzoylhexahydro- 1H-furo( 3 ,4-c )pyrrole.

6. A compound of claim 1 which is 5-(pchlorophenethyl )-hexahydrol H-furo( 3 ,4-c )pyrrole hydrochloride.

i hexahydrol H-furo( 3,4-c )pyrrole.

14. A compound of claim 1 which is chlorobenzoyl-hexahydro-l H-furo( 3 ,4-c )pyrrole.

15. A compound of claim 1 which is 5-propionylhexahydrol H-furo( 3 ,4-c )pyrrole.

16. A compound of claim 1 which is 5-nicotinoylhexahydrol H-furo( 3 ,4-c )pyrrole.

17. A compound of claim 1 which is 5(2,6- dimethylbenzoyl hexahydrol H-furo( 3,4-c )pyrrole.

18. A compound of claim 1 which is 5- chlorophenylacetylhexahydro-1H-furo(3 ,4-c )pyrrole.

19. A compound of claim 1 in a pharmaceutical carnor.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1

Page 1 of 2 DATED October 7, 1975 INVENTOR(S) Alfred D. Miller It is certifir' that error appears in the above-identified patent and that said Letters Patent are hereby corrected -s shown below:

Column 2, line 5, after the words "include aroyl" and before the word "substituted" insert radicals Column 2, line 48, "atomss" should read atoms Column 3, line 59, after "5- (m-trifluoromethylbenzoyl) hexahydrolHfuro(3,4.-c)pyrrole;" and before "5-(ochlorophenylacetyl)- hexahydro-lH-furo(3,4c)pyrrole;" insert 5-cinnamoyl-hexahydrolH-furo(3,4c)pyrrole;

Column 5, line 8, "VII" should read VIII Column 5 line 8, "shwon" should read shown Column 5, line 12, "hexahydro-l(3,4-c)pyrrole" should read hexahydrolH-furo(3,4-c)pyrrole Column 7, line 24, "iwth" should read with Column 7, line 43 "formulaa" should read formula Column 11, line 61, "Hexahydro-lH-furo(3,4-pyrrole" should read Hexahydro-lH-furo(3',4-c)pyrrole Column 11, line 65, (C H NOCL) should read (C H NOCl) Column 13, in structure in Example 20, "CL" should read Cl Column 13, in structure in Example 23, "CL" should read Cl Column 13, in structure in Example 24, "CL" should read Cl Column 13, in structure in Example 25, "CL" should read Cl UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,910,950 Page 2 of 2 DA I October 7, 1975 INVENTOR( 1 Alfred D. Miller It is certified that error appears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column 14, line 23, "5.13" should be deleted and after "63.54" and before "5.31" should be inserted 6.13

Column 15, structure under Example 30, 0 N-" should read O N- Column 15, structure in Example 35 "CI." in both places should read Cl Column 20, line 48, "70,96%" should read 70.96%

Column 24, line 15, "5-(o-acetoxybenzoyl)hexanhydro-lH-furo- (3,4-c) pyrrole should read 5-(o-acetoxybenzoyl)hexahydrolH-furo(3,4-c)pyrrole Column 24, line 50 "milliggrams" should read milligrams Column 28, line 10 "5chlorophenylacetylhexahydro-lH-furo(3,4-c)

pyrrole" should read 5-chlorophenylacetyl-hexahydro-1H- furo(3,4-c)pyrrole Signed and Scaled this Twelfth Day of April 1977 [SEAL] A ties t:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner oflalents and Trademarks 

1. A COMPOUND REPRESENTED BY THE FORMULA
 2. A compound of claim 1 wherein R is a radical selected from the group consisting of phenethyl, chlorophenethyl, hydrogen, cyclohexyl, benzoyl, benzyl, chlorobenzoyl, phenylacetyl, chlorophenylacetyl, chlorophenoxyacetyl, propionyl, nicotinoyl, trifluoromethylbenzoyl, dimethylbenzoyl, thenoyl, trimethylbenzoyl, propenyl, hydroxyethyl, benzenesulfonyl, hydroxybenzoyl, cinnamoyl, naphthoyl, and the pharmacologically acceptable acid addition salts thereof.
 3. A compound of claim 1 wherein R is a radical selected from the group consisting of hydrogen, o-acetoxybenzoyl, 2,4,6-trimethylbenzoyl, 2,6-dimethylbenzoyl, o-hydroxybenzoyl, p-chlorophenethyl, benzyl, cyclohexyl, phenyl, benzoyl, 1-naphthoyl, p-chlorobenzoyl, m-chlorobenzoyl, o-chlorobenzoyl, m-trifluoromeThylbenzoyl, cinnamoyl, o-chlorophenylacetyl, m-chlorophenylacetyl, p-chlorophenylacetyl, hexahydrobenzoyl, propenyl, m-methoxybenzoyl, thenoyl, phenethyl, phenylacetyl, p-chlorophenoxyacetyl, propionyl, nicotinoyl, hydroxyethyl, benzenesulfonyl, and the pharmacologically acceptable acid addition salts thereof.
 4. A compound of claim 1 wherein R is a radical selected from the group consisting of benzoyl, naphthoyl, phenacetyl, p-chlorobenzoyl, m-chlorobenzoyl, o-chlorobenzoyl, m-trifluoromethylbenzoyl, cinnamoyl, o-chlorophenylacetyl, m-chlorophenylacetyl, p-chlorophenylacetyl, p-chlorophenoxyacetyl, propionyl, m-methoxybenzoyl, 2-thenoyl, 2,4,6-trimethylbenzoyl, 2,6-dimethylbenzoyl, 3-nicotinoyl, and o-hydroxybenzoyl, and the pharmacologically acceptable acid addition salts thereof.
 5. A compound of claim 1 which is 5-benzoyl-hexahydro-1H-furo(3, 4-c)pyrrole.
 6. A compound of claim 1 which is 5-(p-chlorophenethyl)-hexahydro-1H-furo(3,4-c)pyrrole hydrochloride.
 7. A compound of claim 1 which is 5-phenylacetyl-hexahydro-1H-furo(3,4-c)pyrrole.
 8. A compound of claim 1 which is 5-(2-thenoyl)-hexahydro-1H-furo(3,4-c)pyrrole.
 9. A compound of claim 1 which is hexahydro-1H-furo(3,4-c) pyrrole.
 10. A compound of claim 1 which is 5-cyclohexyl-hexahydro-1H-furo(3,4-c)pyrrole.
 11. A compound of claim 1 which is 5-(p-chlorobenzoyl)-hexahydro-1H-furo(3,4-c)pyrrole.
 12. A compound of claim 1 which is 5-phenethyl-hexahydro-1H-furo(3,4-c)pyrrole.
 13. A compound of claim 1 which is 5-phenyl-hexahydro-1H-furo(3, 4-c)pyrrole.
 14. A compound of claim 1 which is 5-chlorobenzoyl-hexahydro-1H-furo(3,4-c)pyrrole.
 15. A compound of claim 1 which is 5-propionyl-hexahydro-1H-furo(3,4-c)pyrrole.
 16. A compound of claim 1 which is 5-nicotinoyl-hexahydro-1H-furo(3,4-c)pyrrole.
 17. A compound of claim 1 which is 5-(2,6-dimethylbenzoyl) hexahydro-1H-furo(3,4-c)pyrrole.
 18. A compound of claim 1 which is 5-chlorophenylacetylhexahydro-1H-furo(3,4-c)pyrrole.
 19. A compound of claim 1 in a pharmaceutical carrier. 